Another help me upgrade thread

[Nieldo]

Currently have:

Slot 1: 512MB PC3200 Kingston HyperX with 2-3-2-6-1
Standard 64M X 64 Non-ECC 400MHz 184-pin Unbuffered DIMM

Slot 2: 256MB PC3200 Kingston HyperX with 2-3-2-6-1
Standard 64M X 64 Non-ECC 400MHz 184-pin Unbuffered DIMM

Slot 3 and 4: Empty.

Ive been looking in Ebay and have found some more of the same kingston stuff but I was wondering, what would you guys recomend?

 

[Nieldo]

Whats the difference between DDR and DDR2?

Will most mobos support DDR2 if they work with DDR fine??

http://www.overclockers.co.uk/acatalog/Online_Catalogue_This_Week_Only_25.html#aMY_2d046_2dGL

How long is that offer for?